Metal molding.



R E R F. D 0 N K rm um & N 0 S N B 0 R Pm W METAL MOLDING.

APPLICATION FILED MAY I2 I91]- Patented Dec. 10, 1918.

4 SHEETS-SHEET I INVENTOR was...

WITNESSES w. TIL-ROBINSON & H. G. KNODERER.

METAL Momma.

00 1 9 l 0 1 0w AU D d Du t H flu LIU a D1. m 74 VI A H U E R F Y m T A W L P D! A 4 SHEETS-SHEET 2- WITNESSES W. (I. RDBINSON & H. G. KNODERER.

I METAL MOLDING. APPLICATION man my i2. 191:.

, Patented Dec. 10, 1918.

4 SHEETS-SHEET 3.

F'IG.ZD.

INVENTOR W. C. ROBINSON & H G. KNODERER.

METAL MOLDING. APPLlCATlCN FILED MAYIZ; 13H.

- I Patented Dec. 10, 1918.

4 SHEETS-SHEET 4- WITNESSES.

. memos. Y

' sans Y ENT carton;

wrLIsIAM c. ROBINSON, or snwiciznnr AND. noimn. e. KNOIDERER, or nnenwoa'rn,

PENNSYLVANIA, AssmNoas To 'NArrIoNAL METAL BTIRGH, PENNSYLVANIA, A. CORP RATION OI PENNSYLVANIA.

METAL MOLDING.

' Specification f Letters Eatent.

To all whom it may concern States, have invented or discovered certain.

new and usefulllmprovements in Metal Moldings, of which improvements lowing is a specification.

The invention described herein relates to electrical conductor conduits, and has particularly to do with conduits known as metal moldings which are usually applied to the surface of wallsor other supports either forv original installations or for the extension of circuits fromr conductors carried in inner-wall conduits.

The metal molding contemplated herein may be considered as consisting oftwo elements, namely, tings. There arerin general two types of conduits, those'formed of a single piece of metal and which are usually substantially elliptical,

and those formed in two parts, a base and akcap, suitably held together. In

making installations of two-part conduits.

may be secured after which the be laid therein one part, usually the base, to the supporting surface, electrical conductors may and the cap-then applied; or the cap and base may be first asse' bled and", the con ductdrs fished through them. The present invention contemplates bothone and twopiece conduits regardless of their intended manner of installation. i

7 ing the conduit The conduit fittings, the second of theabove named elements of' metal :molding,

include all forms of members for connect to'junction or outlet boxes, sockets; sw tches, etc.,' or for connecting the -conduits to'each othersuch'as butt-joints,

" elbows, Ts, crosses, etc.

factured these fittings are usually, if not always, made-of two parts,- a base and a cap; adapted, when assembled, 'to lie-either directly or indiiectly connected to each other,

As actually manuthe folconduits and conduit 'fitworkman may, as by such two-part fittings.

One of the essential requirements of an installation of metal molding is that'the conduits and fittings beso connected to each other asto afl'ord,a pathof electrical conductivity from the remotest point of the molding to the ground, so that, in case of conductor trouble, the current may be grounded. In two-part conduits it is usually required'that this path of conductivity be established through the conduit and fitting bases; accordingly the terms conduit base or fitting base, as 'theyhereinafter appear in the specification and claims, are used. to designate those parts of the conduits and fittings that are electrically connected to each other for the purpose described, and

'this quite irrespective of the configuration 1establishment; of proper electrical connections has been made a requisite to the complete mechanical assembly and connection of all the necessary parts of the molding. That is to say, in the installation of molding here tofore provided, a careless or indifferent cutting the conduit sections too short or by'other acts or omissions, completely-assemble all the essential parts of conduits and fittings without havestablished an adequate electrical bond ateach point of connection, and frequently such a condition cannot be detected after the installation is completed. Accordingly, the principal object of the present invention is to provide metal molding which cannot be fully or completely assembled until adequate electrical connections have been estab lished between the conduits and fittings.

MOLDING COMIEANY, OF PITTS- I Patented Dec. 10, 1918 A further and more specificobjectof the invention s to provide metal molding characterized as v nst stated, and wherein the laterally applicable mechanical and electrical connections between conduits and fittings are effected by snap connecting and bondingmembers. I I

A still further object is to provide such v metal molding conduits, and,fittings wherelengths,

in'the conduits need not be cut to precise and wherein .both one and twopiece conduits may be used interchangeably with the fittings.

In the accompanying sheets ofdrawings forming part 0 our specification we have illustrated the preferred embodiment of our invention. Figure 1 is a perspective view of two-part conduits assembled with the base members of an L and of butt coupling" fittings, the fitting caps being shown above the bases in positions to be laterally applied,

thereto; Figs. 2, 3, 4 and, 5 are transverse sections indicated, respectively, by the lines IIII, III-III, IVIV and VV, Fig.

' 1, thecaps being applied to the bases; Figs:

'jrespectively, plan and side views of the base .member of the T-fitting of Fig. 8, while a molding conduit to a cross-fitting two-piece conduit preferably used is of 6 and 7 longitudinal sectional views indicated, respectively, by the lines VI -VI and VII-VII, Fig. 1; Fig. 8 a planview of a T-fitting assembled with two-part conduits, the modifications necessary to enlarge the T I being indicated by dotted lines; Fig. 9 a sectional view taken on the line IX1IX, Fig. 8"; Figs. 10 and '11. are,

Figs. 12 and 13 arecorresponding views of the cap member; Fig. 14: is'a plan view of the base member, and Fig. 15 a plan view of the cap member, of a fitting for attaching to an outlet or similar box; Figs. 16 and "17 are left end views of the base and cap fitting members shown, re.- spectively, in Figs. 14: and 15;Fig.- 18 is a sectional view taken on the line 'XVIII; XVIII, Fig. 14, thecap of'Fig. 15" being assembled with the base of Fig. 14., and asingle-piece molding conduit, being shown assembled with thefitting; F igs; 19. and 20 j are plan views, respectively, of base and cap fitting members similar to thoseshown in F igs. l4- and 15; Fig. 21' is a side-view of the fitting cap of Fig. 20; 22 a sectional view taken on the line XXII.XXII, Fig.

19, the cap of Figs. 20 and 21 being assem-' are formediat the .ends of the base.

form shown in Figs. land 2, and comprises 66 a base 1 of substantially semi-elliptical shape having inwardly turned edges 2, and

a cap 3 adapted to rest upon such edges.

To hold the cap to thebase, spring clips 4:, suchlas shown in.Figs. l and 5, may be snapped around the assembled base 1 and cap 2 at suitable intervals, su h clips being provided with inwardlyturned edges adapted to grip the side walls of the base 1. As will presently appear more fully, the clips fittings. Longitudinal and cross-sectional views of the single-piece conduit 6 which may also be used are shown, respectively, in Figs. 18 and 22. It will be observed of the two-piece conduit 1, 3 that its outermost pointslie in the contour of the outer wall of the single-piece conduit 6, thus making it possible to use such conduits interchangeably with the fitting.

ThetWo-part fittings used in conjunction with the conduit'are so constructed that the electrical bonding of the conduits to the fitting bases must precede the assembly attachment of the fitting caps to such bases. In the illustrative embodiment of the invention'a.

single means is provided for the mechanical and the electrical bonding attachments of conduits and fitting bases, the same preferably comprising a pair of spring arms 7 maybe used 'for attaching the fitting caps to their bases, it is preferred that they be indirectly attached, as by attaching them to the conduits after the conduits have been attached to thebases. For this purpose the 96 between which the conduit may, by lateral pressure, be snapped, While various means capsare preferably provided with. spring arms 8 similar to the arms 7 of the bases, eferring particularly to the L-fitting shown in Fig. 1, it will be seen that the springarms 7 are,spaoed from the main body portionof the base. Specifically, they Adjacent to such arms .(and connecting them. to the central or main body portion 9 of the base) there are tongues 10- which are slightly longer than the width of the cap arms 8, whereby to provide spaces for such arms. It will be readily understood that, in making installations of metal molding thus constructed, it becomes necessary, in order to attach the cap-11 to the-base, to havea portion of the end of theconduit l, 3 (or at least the base portion 1) projecting beyond the inner edges of the arms 7 to receive the arms 8. That is to say, unless the conduits I l and overlap a portion of the tongues 10, the cap arms 8 cannot engage the conduits and hence cannot be assembled in their contemplated operative relation with the bases.

Asr shown in Figs. 1 and 2,'the conduit do thus project beyond the edges of the arms 75 4; may also be used as caps for the'butt-joint 1, 3 at the left end as indicated at the right end-of. this fitting.

I 1 Preferably, m

the bottom and side walls of the central portion 9 and thetopland side 'walls of the central portion 11 of the cap are, as indicated in Fig. 6, so formed that they provide a conductor passageway of substantially the same interior form'as the} p cap of this fitting is'also conduit 1, 3, thus eliminating abrupt abrading edges or corners, and forming stops for the ends of the conduits. P In Fig. 1 there is also shown a butt-coupling fitting for connectin and bonding adjacent ends of conduits lying in the same general straight line. The base member of this coupling comprises a central tongue 10 with adjoining spaced pairs of spring arms 7 adapted to engage the conduits and electrically bond them together. The spring clip 4 is used as a cap for this fitting and is assembled with the base by being snapped upon the ends of the conduits 1, 3 between the spaced pairs of arms 7 The conduits,

as already explained, must have the full intended electrical bond with the arms -7 be? fore the conduits will overlap the tongue 10 sufficiently to afford points of en agement for the spring clip of cap4 with oth conduits.

Figs. 8 to 13, inclusive, show the assembly and details of the bases and cap members of a T-fitting, wherein the bonding of the fitting base with the conduits, and the assembly of the fitting 'members isefiected in the same manner and with the same advantages as fully described and explained with reference to the fittings of Figs. 1 and 7, inclusive. The base member, shown particularly in Figs; 10 and 11, is provided with three pairs of conduit connecting and bonding spring arms 7 spaced from the main body portion of the'base, and thecap, shown in detail in Figs. 12 and 13, is provided with similar arms 8 which engage the conduits at points nearer their ends than do the arms 7. Because T-fittings are usually used at junctions of conductors, the top 13 of the cap is bulged outwardly to afford space for the necessary insulation wrapping. at thejunction. As already explained, the dotted upper portion of Fig. 8 indicates the modification of form necessary to make a cross-fitting'of the same general construction as the T-fitting shown in full lines.

In Figs. 14 to 18, inclusive, there is shown a fitting for'connecting a conduitto an out- My of the provided with a pair of arms 7 for engag ing a conduit and bonding it with-the box 14; while-.thecap is attachedto the base through the engagement of the conduit 6 by the cap. spring arms8. For attaching the inner end of the'base member to the'box, such end is provided withoutwardly curved 1 spring arnis 15 adapted to engage the walls of the box-*adjacent'to the opening therethrough. Theshape of these arms is such that the fitting may be used either? with the, round boxsho'wn iniull lines or with a' box havin -a plane faced wall as indicated in dotte lines at 16. In a similar manner the wardly curved arms 15 for engaging the box walls when the several parts are assembled.

provided with. outplained, is intended to be used when the box opening is of the requiredsize to receive the molding to be. connected to. the box. It is sometimes. desirable to connect small two Wire molding to a boxprovided with large openings for four wire molding. For this purpose the attaching and bonding fitting 'may be constructed as shown in Figs; 19 to 22, inclusive. This fitting differs from that just explained .only'in thatthe base mem- I her is provided with a slotted tongue 17 whereby the base may be attached to a box by a screw 18, and in that the base is further provided with laterally extending wings 19 adapted to fill the lower otherwise unclosed portion of thfopenin in the box. 20; while in a similar manner tie inner end of the'cap of this fitting is provided with a wing 21 to. fill the upper. otherwise unclosed portion of such opening.

In Figs. 23, 24 and 25there is shown an internal elbow for connecting and. electrically bonding conduits lying in different planes and disposed at an angle to each other... Such fittings are frequently used at corners formed at the junctionpf two walls Y or of a wall and ceiling. It is only necessary to. explain with respect to this fitting that the base member 22 is provided at its outer ends with pairs of spring arms 7 for mechanically. connecting and electrically bonding the two conduits 1, 3, and that the cap 23 is also provided with two pairs of spring arms 8, which, for the purposeof assembling the cap with the base, engage trical bond has been established between the conduits and fitting bases, and this for the reason that no means are provided whereby the cap member can be attached to the base unless the conduit is in its proper position on, and bonded with, the base. Furthermore, either one or two-piece conduits may be used with the fittings, and both may be connected to the fitting bases by lateral application rather than by sliding the conduits longitudinally. According to the'provisions of the patent statutes we have described the principle and operation of our invention and have explained in detail the construction of the metal molding which we now consider to represent the best embodiment thereof. However, we desire to have it understood that the invention may. be practised by other forms of moldin than that particularly shown and descrified. i

We claim as our invention: ,1. The combination with a conduit base for electrical conductors, of a conduit fitting comprising a base and cap assembled with saidconduit base, said conduit base and fitting base being-constructed of elec-' tr1cal conducting material and having overlapping current-transmitting contact faces,

complete electrical bonding contact between said conduit base and fitting base beln requisite to effect complete assembly of said ca -with said fitting base;

2. The combination with a conduit base for electrical conductors, of a; conduitfitting comprising a fittingbase provided with means for attaching and electrically bonding- 1t to said conduit base, said conduit base and fitting base being constructed of I electrical conducting material and having overlapping current-transmitting contact faces, and a cap provided with. means for attaching it to said conduit base,;the capattaching means being ineffective for such purpose prior to the attachment and bond-' ing of the fitting base to said conduit base. 7

3. The combinationwith a condiiit base for electrical conductors, of a conduit fit- }tlng comprising abase and a cap, said con du t-base and,fitt1ng base being construct-' ed of electrical conducting materilal and having at their points of assembly currenttransmitting faces, said fitting base bein q provided with means for electrically bon ing it 'with said conduit base, and said caphaving means for mechanically attaching it to said conduit base, said bonding andsaid cap attaching means being spaced with relation to each other and longitudinally of said conduit base whereby the cap-attaching means may enga e' said conduit base wgen and only when t e conduit base is fitte t said bonding meansof said fitting base.

for electrical conductors, of a conduit fitting comprising a base and a ca each having means gripping said conduit b duit base and fitting base being constructed of electrical conducting material and having current-transmitting faces at the gripping noint of the conduit base by the fitting base, the gripping means of the cap being spaced with relation to the gripping means 'of the fitting base and longitudinally of said conduit base whereby the gripping transmitting faces, the fitting base including amain body portion and means spaced therefrom gripping said conduit base, and

said cap being provided with conduit-gripping means eflective to en age said condult base only when a portiont ereof lies in the space between the mainlbody portion and conduit gripping means of said fitting base.

6. In a metal molding installation, the combination of a pair of' conduit bases hav- 1 ing their ends adjacent to each other, and a fitting comprising a base havinga pair of conduit-grippingpmeans each engaging an,

end of said conduit bases, said conduit bases ase, said con- '100 and fitting base being constructed of elec- Y trical conducting material and having current-transmitting faces 'at the gripping 3 points of the conduit bases by'the. fitting base, said means being spaced apart and the ends of the conduit bases lying in such. space, and a cover engaging sa1d. condult basesbetween-the points of engagement of the conduit-gripping means of said fitting base. s

7. The combination with a conduit base for electrical conductors, ofa conduit fitting comprisiii a base and a cap, said conduit base and tting base being constructed of electrical conducting material and said fitting base receiving and making "overlapping electrical contact with said conduit base, said cap being applied to said fitting base and secured thereto solely by engagement with said conduit base and only after the conduit' base has been received by and brou ht into electrical contact with said fitting ase;

8. The combination with a conduit base for electrical conductors, of a fitting ineluding a base provided with arms engaging 'said' conduit base and forming an electrical bond therewith, said conduit base and fitting base being constructed of electrical conduct- The combination with a conduit base ing material, and a cap provided with arms engaging said conduit base at a point nearer to the end thereof than the point of conduitengagement of said fitting arms, said cap and fitting base being connected to each other solely through the engagement oftheir respective arms with said conduit base.

9. The combination with a conduit base for electrical conductors, of a' fitting 001111 prising a base provided at one end with a single means for the attachment and elec trical bonding of said conduit base thereto,

, sembly of conduit base, cap and fitting base,

efi'ective only after the attachmentand electrical bonding of said conduit base and fitting base by the aforestated means therefor.

10. In a metal molding installation, the combination of a fitting base provided at its outer end with arms for receiving a conduit base for electrical conductors and at its bottom with atongue extending from the inner edges of said arms, a conduit base engaged by said fitting base arms and having a portion of its end overlapping said tongue, said conduit base and fitting base being constructed of electrical conducting material and having at their point of assembly current-transmitting faces, and a cap provided with means, for engaging said overlapping )portron/ of the conduit base.

11. In a metal moldinginstallation, the

' set our hands.

combination of a fitting base prdvided at its outer end with arms for receiving a conduit 'base' for electrical conductors, and at its 'bottom with a tongueiextendmg from the inner edges of saidarms, a conduit base engaged-by said fitting basearms and having a portion of its end overlapping said tongue,

said conduit base and fitting base being constructed of electrical conducting material and having at their point of assembly current-transmitting faces, and a cap. provided I with arms engaging said overlapping porv .tion of said conduit base.

12. The combination with a conduit base for electrical conductors, of a conduit fitting comprising a base and a cap, said conduit base and fitting base being constructed of electrical conducting material, said fitting base being provided with means for effecting electrical bonding connection withsaid I conduit base, and said cap being provided with means for mechanically attaching it to said conduit base, the effecting of said bonding. connection between said conduit base and fittingbase being, in the complete assembly of cap, fitting base and conduit base, a requisite to the efi'ecting of said me.-

chanical attachment of said cap to said conduit base. v

In testimony whereof we ,havehereunto WILLIAM c. RoBiNsoN. HOMER e. KNODERER.

Witnesses:

G. ROY KERR, J. M.G.. TALLMAN. 

